Lipooligosaccharide a potent endotoxin

Endotoxin

Endotoxins are toxins associated with some Gram-negative bacteria. An "endotoxin" is a toxin that is a structural molecule of the bacteria that is recognized by the immune system.-Gram negative:...

, causes:

• Petechiae,
• Purpura
  Purpura
  Purpura is the appearance of red or purple discolorations on the skin that do not blanch on applying pressure. They are caused by bleeding underneath the skin...
  
  ,
• Waterhouse-Friderichsen syndrome
  Waterhouse-Friderichsen syndrome
  Waterhouse-Friderichsen syndrome or hemorrhagic adrenalitis or Fulminant meningococcemia, is a disease of the adrenal glands most commonly caused by the bacterium Neisseria meningitidis. The infection leads to massive hemorrhage into one or both adrenal glands...
  
  ,
• Septic shock
  Septic shock
  Septic shock is a medical emergency caused by decreased tissue perfusion and oxygen delivery as a result of severe infection and sepsis, though the microbe may be systemic or localized to a particular site. It can cause multiple organ dysfunction syndrome and death...
  
  

Lipooligosaccharides are naturally occurring variants of the more common glycolipid, lipopolysaccharide. While lipopolysaccharides are common in the enteric bacteria, LOS is present in bacteria that colonize those mucosal surfaces that are not bathed in bile. LOS is a highly phase variable molecule.

LOS is clinically relevant in Neisseria meningitidis

Neisseria meningitidis

Neisseria meningitidis, often referred to as meningococcus, is a bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life threatening sepsis. N. meningitidis is a major cause of morbidity and mortality during childhood in industrialized countries...

infections, where it has been shown to correlate with the severity of disease, as well as cause the complications listed above which are hallmarks of meningococcal meningitis

Meningitis

Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...

.